Amoxicillin Pediatric Dosage

Choose a standard or high-dose regimen to determine mg/kg dosing and equivalent suspension volume per dose based on the child's weight.

80–90 mg/kg/day divided q12h

Common strengths: 125, 200, 250, 400 mg per 5 mL.

Dosage Results

Daily dose

1620 mg/day

90 mg/kg/day × 18.00 kg (capped at 4000 mg/day).

Per dose (q12h)

810 mg

10.1 mL per dose (suspension 80.0 mg/mL).

Round liquid doses to the nearest 0.5 mL. Verify with a pediatrician or pharmacist before dispensing.

How to Use This Calculator

1

Confirm the child's weight

Weights should be recent; dosing is highly weight-dependent.

2

Select the regimen

Use high-dose (80–90 mg/kg/day) for otitis media, sinusitis, community-acquired pneumonia, or penicillin-non-susceptible pathogens.

3

Enter suspension strength

The tool converts mg per dose to mL using the selected concentration.

Formula

Daily dose (mg) = weight (kg) × regimen mg/kg/day.

Based on American Academy of Pediatrics high-dose amoxicillin recommendations (80–90 mg/kg/day) and standard dosing guidance (40–50 mg/kg/day).

About Amoxicillin Dosing

Amoxicillin is the first-line treatment for many pediatric bacterial infections. High-dose regimens overcome intermediate resistance in Streptococcus pneumoniae. Duration depends on the infection: 5–7 days for otitis, 7–10 days for sinusitis, and 10 days for streptococcal pharyngitis (with amoxicillin 50 mg/kg once daily or 25 mg/kg twice daily).

Monitor for allergic reactions, gastrointestinal upset, or rash. Adjust dose in renal impairment. Counsel caregivers on measuring liquid doses with an oral syringe.

Frequently Asked Questions

What is the max daily amoxicillin dose?

Typically capped at 4,000 mg per day, even for high-dose regimens.

How should doses be rounded?

Round to the nearest 0.5 mL (or 5 mg tablet increment) and confirm with a pharmacist.

Can I split the daily dose into three doses?

Yes—some regimens use q8h dosing (three times daily). Adjust doses per institutional guidelines.

Should renal impairment change the dose?

Yes. Reduce dose or extend interval if eGFR <30 mL/min/1.73 m²—consult pediatric nephrology.

Can amoxicillin be taken with food?

Yes—food does not significantly affect absorption and may reduce stomach upset.